Breast pumps are well known, but the field of naturally shaped breast milk collection devices with self-contained breast milk reservoirs which work with breast pumps and can be used discreetly by fitting them within a woman's brassiere, often under ordinary clothing so that a woman can use a breast pump around others discreetly, is relatively new. The only known devices in this field, upon which this invention improves, are taught in U.S. Pat. Nos. 7,559,915; 8,118,772, and 8,702,646 (Dao, Garbez), the disclosures of which patents are incorporated by reference herein.
The above-mentioned patents disclose a milk collecting reservoir generally cup-shaped to fit into a lactating woman's brassiere, which reservoir is adapted to be disconnected from a pump and emptied when full after hands-free operation, whereby the milk can be transferred to a feeding or milk storage device such as a baby bottle, pliable storage bag, or other suitable container.
Prior to the development and use of breast pump devices with self-contained breast milk reservoirs, breast pumping by new mothers was conducted in private, where noise produced by the breast pump assemblies was not a problem. As a result the reduction or elimination of noise while expressing milk from a mother's breast has never been a design focus in the development of breast pump systems. However, with the introduction of breast pump devices with self-contained reservoirs, breast milk pumping and expressing now takes place discreetly, but in public places, such as the desk or office of a lactating working mother. In these latter situations, it is desirable that the milk pumping system produces little or no noise so as not to distract nearby personnel, or to draw unnecessary attention to the mother using the breast milk pumping device.
Sound is a form of energy created when air is caused to vibrate, such as when air is forced through a tube at rapidly changing pressures. This energy travels outward in the environment away from the sound source since the air in the environment carries sound waves, and objects as well as the air in the environment vibrate in sympathy until the remaining energy reaches one's ears. An object of sound suppression techniques is to interrupt and/or divert the chain of vibrating air flow at some point between the source of the vibration and one's ears.
Since sound comprises long-wavelength sound waves, sound energy can easily move through most solids and emerge loudly on the other side of the solid mass as the air on the other side of the solid mass vibrates again. Noise can be suppressed by preventing the direct movement or flow of air from the air outlet of a breast pump vacuum system to the atmosphere surrounding the breast pump vacuum system, thus creating an indirect air flow. One way to suppress noise in such system is to interfere with the path the sound is likely to take before reaching one's ears through the use of absorbent rubbery or porous foam material that “soaks up” or absorbs sound energy before the sound energy reaches the environment. Such sound absorbent materials include, among others, thread-like glass fiber materials, porous foam, and neoprene rubber. Baffle structures may also be used to divert the path of the moving air, thus interfering with the direct movement of air from the air outlet to the atmosphere.
Therefore, an object of the present invention is to provide a compact noise suppressing or muffler system for reducing or eliminating noise emanating from a breast pump assembly. In addition, the compact construction of the presently disclosed and described device may have other applications where it is desirable to reduce or eliminate noise generated by a small or medium sized air pump system.